Yes, in a perfect world only those who believe others should suffer as long as possible would be the ones who die slow painful deaths, but the world is not perfect, so it unfortunately happens to decent folks as well. We do treat animals better and that is a sad commentary on society.
Even more sad is the old laws forced some people to cut their lives short earlier - killing themselves when they are still physically able because they fear the day they won't be capable of doing it themselves.
Certainly tight controls need to be in place, but most important - and this was important even before this ruling - make sure your family and friends knows your wishes. Many people already have "living wills", I would suggest everyone should make sure their wishes are known before hand. It may not make for the happiest dinner conversation, but it is a conversation well worth having sooner rather than later.
Here is a template from our local health authority. You will find many others on the internet.